Modular chiller heater reversing/non-reversing conversion apparatus and method

ABSTRACT

A chiller heater building air space conditioning system is set out including a plurality of interconnected modular chiller/heater units which can be operated variously in a chilling mode, a heating mode, or an off mode. An arrangement for converting a system comprising reversible modular heat pump chiller heater elements into a system comprising non-reversible modular chiller heater elements is set out.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus and method for converting a modular reversing chiller/heater system to a modular non-reversing chiller heater system.

2. Description of the Related Art

In the past, various systems have been proposed for providing an energy efficient system for building air space conditioning, where a building may require variously simultaneous heating and cooling. Such systems are set out, for example, in U.S. utility patent application Ser. No. 12/562,931 and U.S. provisional patent application number 61/447,247.

The first such system in the world to utilize a plurality of modular reversible heat pump chiller heater units utilizing a system of virtual moveable endcaps is described in U.S. Utility patent application Ser. No. 12/562,931. This application disclosed for the first time an arrangement of interconnected reversible heat pump chiller heaters having on one side of each modular unit one or more building conditioning fluid loop connections for alternately chilling or heating building/conditioning fluid. The system allows for each modular unit to be operated and interconnected in a manner by which flexibility in providing various arrangements of heating, cooling, and simultaneous heating and cooling to a building is provided, as well as selective resting of particular units.

A ground or water source heat sink/source could be variously utilized on the other side of each modular unit opposite the building load.

This system provided many advantages but meanwhile suffered from certain drawbacks, one of which was that by virtue of the reversible nature of the individual modular units, significant design compromises were inherent which led to a reduced energy efficiency compared to non-reversing units.

An improved system was set out in U.S. Provisional Patent Application No. 61/447,247, whereby the flexibility of interconnected modular units could be realized, but which for the first time disclosed an arrangement whereby each modular unit was a non-reversing chiller heater, instead of a reversing heat pump chiller heater. This system realized significant gains in energy efficiency over the previously disclosed reversing system.

Meanwhile, a need existed to allow for the conversion of the relatively inefficient modular reversing heat pump chiller heater system to a non-reversing mode, in order to realize the inherent efficiency advantages.

BRIEF SUMMARY OF THE INVENTION

In view of the aforementioned drawbacks in certain prior art chiller heater systems, a new system is proposed which achieves the objects of flexibility and energy efficiency.

It is an object of the invention to set out a system of interconnected modular chiller heater units which can variously be operated to provide chilling, heating, and/or simultaneous chilling and heating to a building load, as well as resting of particular units.

Specifically, it is an object of the invention to set out a system of interconnected reversible heat pump chiller heater units which are originally installed in an arrangement whereby each unit is operable in a reversible mode, and which by virtue of the present invention are modified to operate in whole or in part as non-reversing units.

More particularly, it is an object of the invention to set out a system which converts a system of interconnected modular reversible heat pump chiller heaters utilizing a ground or water source heat sink/source to a system of non-reversing chiller heaters capable of being selectively operated to variously provide cooling, heating, simultaneous cooling and heating, or to be rested as required.

BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS

FIG. 1 is a schematic drawing of a prior art arrangement of interconnected reversible modular heat pump chiller heaters.

FIG. 2 is a schematic drawing of a modification of prior art arrangements of interconnected reversible modular heat pump chiller heaters.

FIG. 3 is a schematic drawing of a reversing system converted to a non-reversing system.

DETAILED DESCRIPTION OF THE INVENTION

Following is a listing of elements of the invention.

-   1. Building to be conditioned -   2. Second side building fluid manifold -   3. First side building heat exchanger -   4. Second side building heat exchanger -   5. First side evaporator/condenser -   6. Second side condenser/evaporator -   7. Alternate chilled fluid/heat sink/source three way valve -   8. Ground/water heat sink/source -   9. Ground/water heat sink/source heat exchanger -   10. Reversing refrigerant working fluid loop -   11. Alternate heated fluid/chilled fluid three way valve -   12. Second side reversible chiller heater isolation valve -   13. First side reversible chiller heater isolation valve -   14. Building conditioning fluid loop -   15. Virtual moveable endcap building fluid isolation valves -   16. Chilled fluid isolation valve -   17. Heated fluid isolation valve -   18. Heated fluid bypass circuit -   19. Heated fluid bypass circuit isolation valve -   20. Heated fluid building load isolation valve -   21. Alternate chilled fluid/heat sink/source three way valve -   22. Heat sink/source isolation valve -   23. Non-reversing refrigerant working fluid loop -   24. Evaporator -   25. Condenser -   26. Chiller/heater module -   27. Modular reversing heat pump chiller/heater -   28. First side building first fluid manifold -   29. First side building second fluid manifold

FIG. 1 sets out a prior art modular reversing virtual moveable endcap chiller heater system, as set out in U.S. Utility patent application Ser. No. 12/562,931.

A series of chiller/heater modules 26 are arranged to variously be employed to provide chilled or heated building conditioning fluid via a building conditioning fluid loop 14 to a first side building heat exchanger 3, a second side building heat exchanger 4, or a ground water heat sink/source heat exchanger 9. A modular reversing heat pump chiller/heater 27 includes a reversing refrigerant working fluid loop 10, a first side evaporator/condenser 5, and a second side condenser/evaporator 6.

Modular reversing heat pump chiller/heater 27 can be operated in one direction to evaporate working fluid in the first side evaporator/condenser 5 and condense working fluid in the second side condenser/evaporator 6, and can alternately be operated in the opposite direction, by reversing the flow direction of working fluid in the reversing refrigerant working fluid loop 10, to evaporate working fluid in second side condenser/evaporator 6, and condense working fluid in the first side evaporator/condenser 5.

Virtual moveable endcap valves 15 can be operated to variously deliver heated or chilled building conditioning fluid to the first side building heat exchanger 3, the second side building heat exchanger 4, and/or the ground water heat sink/source heat exchanger 9, depending on the requirements of the building cooling load, heating load, ambient conditions and energy cost considerations.

Also, first side reversible chiller heater isolation valve 13 and second side reversing chiller heater isolation valve 12 can be operated to fully or partially add or remove the energy transfer effect of the respective first side evaporator/condenser 5 and second side condenser/evaporator 6 from contribution to the building conditioning fluid.

In one embodiment, the conversion process from the reversing system of FIG. 2 to the non-reversing system of FIG. 3 is essentially as follows.

Heated fluid bypass circuit 18 is attached in fluid connection with the previous connection between the second side condenser/evaporator 6 and the second side building fluid manifold 2, and the first side building first fluid manifold 28.

Where in the pre-converted system, second side building fluid manifold 2 served the heat sink source 8, in the post-converted system, the second side building fluid manifold 2 serves the building 1 second side heat exchanger 4, normally to provide heat energy to the building space.

In the pre-converted system, first side building first fluid manifold 28 served the second side building heat exchanger 4, normally to provide heat energy to the building space. In the post-converted system, first side building first fluid manifold 28 serves the heat sink/source 8.

In both pre and post converted systems, first side building second fluid manifold 29 may serve the first side building heat exchanger 3, normally to remove heat energy from the building space.

The non-reversing refrigerant working fluid loop 23 would then be operated in such a manner that the previous reversing valve of the previous reversing heat pump chiller heater apparatus would not be required. The working fluid would be circulated such that it would transfer heat from itself through the condenser 25 to either the second side building fluid manifold 2 to heat the building, or to the first side building first fluid manifold 28 to be rejected into the heat sink source 8.

Simultaneously, the non-reversing refrigerant working fluid loop 28 would absorb heat through the evaporator 24, to remove heat from either the first side building second fluid manifold 29 to remove heat from the building space, or from the first side building first fluid manifold 28 to remove heat from the heat sink source 8.

Via virtual moveable endcap building fluid isolation valves 15, modular units 1-n may be selected to variously add or reject heat to either the building space or to the heat sink source 8. Also, individual chiller/heater modules could be rested as required.

In this manner, a modular recovery heat pump chiller heater system may be converted into use as a modular non-reversing chiller heater system, with the attendant energy efficiency advantages of such a system. 

1. A modular heating/chilling apparatus conversion system, comprising: at least two modular reversible heater/chiller units connected in parallel, each of said reversible heater/chillers having a reversible evaporation cycle working fluid loop, an evaporator/condenser heat exchanger circuit and a separate condenser/evaporator heat exchanger circuit, a building load chilled fluid circuit, a building load hot fluid circuit, an external heat sink/source and circuit, modular unit isolation valves between each of said modular units, each of said modular units having a chilled fluid connection circuit, a hot fluid connection circuit, and an external heat sink/source connection circuit, a first side building first fluid manifold, a second side building fluid manifold, a heated bypass circuit in fluid connection with said evaporator/condenser heat exchanger circuit, said first side building first fluid manifold, and said second side building fluid manifold, said second side building fluid manifold prior to connection with said heated bypass circuit serving said heat sink/source and after connection with said heated bypass circuit serving said building load hot fluid circuit, at least one of said modular reversible heater chiller units being thereby operable in a non-reversing mode such that the evaporator/condenser heat exchanger circuit would operate only as a condenser, and the condenser/evaporator heat exchanger circuit would operate only as an evaporator, wherein said at least one of said modular reversible heater chiller units would be operated in a non-reversing mode to achieve higher operating efficiencies.
 2. A method for converting at least one modular reversible heater chiller in a parallel modular reversible heater/chiller system from a reversing mode to a non-reversing mode, comprising the steps of: attaching a heated fluid bypass circuit into fluid connection from a second side condenser/evaporator and a second side building fluid manifold and a first side building first fluid manifold, changing the second side building fluid manifold from serving a heat sink/source to serving a building second side heat exchanger, removing a reversing valve from service in said modular reversible heater chiller, and operating said modular reversible heater chiller in a non-reversing mode, wherein said non-reversing modular reversible heater chiller operates at a higher overall efficiency. 